Devices and methods for delivering energy to body lumens

Abstract

A medical device is disclosed for delivering energy to a body lumen. The device includes an elongate member including a proximal portion and a distal portion adapted for insertion into a body lumen; and an energy delivery device disposed adjacent the distal portion of the elongate member, the energy delivery device including at least one elongate electrode arm, wherein the elongate electrode arm is configured to transition between a first configuration and a second configuration different than the first configuration. The at least one elongate electrode arm includes an active region configured to contact and deliver energy to the body lumen. When the elongate electrode arm is in the first configuration, at least a portion of the active region of the elongate electrode arm extends radially inward toward a longitudinal axis of the energy delivery device.

What is claimed is: 
     
       1. A medical device for delivering energy to a body lumen, the device comprising:
 an elongate member having a proximal end, a distal end, and a lumen extending therebetween; and 
 a basket assembly disposed at or adjacent the distal end and configured to transition between a collapsed state and an expanded state, wherein the basket assembly includes a plurality of expandable legs, wherein a first expandable leg of the plurality of expandable legs includes a first region disposed at or adjacent a proximal portion of the first expandable leg, a second region disposed distally of the first region, an active region disposed distally of the second region, a third region disposed distally of the active region, and a fourth region disposed distally of the third region, wherein the first expandable leg is pre-shaped such that in the collapsed state and while the basket assembly is unconstrained by an outer sheath:
 the second region extends distally and radially outward from the first region, 
 the active region extends distally from (i) the second region in a radially inward curve toward a longitudinal axis of the medical device and toward a radially innermost point, and (ii) the radially innermost point in a radially outward curve toward the third region, and 
 the third region extends distally from the active region and radially inward toward the fourth region; 
 
 wherein the active region is configured to contact and deliver energy to the body lumen when the basket assembly is in the expanded state, and 
 when the basket assembly is in the expanded state, distal ends of the plurality of expandable legs converge toward one another. 
 
     
     
       2. The medical device of  claim 1 , wherein the active region includes an electrode secured to the first expandable leg. 
     
     
       3. The medical device of  claim 1 , wherein the active region of the first expandable leg exhibits a curvature when the basket assembly is in the collapsed state, and when the basket assembly is in the expanded state, the active region of the first expandable leg is substantially flat. 
     
     
       4. The medical device of  claim 1 , wherein portions of the first expandable leg proximal and distal to the active region include an insulating coating. 
     
     
       5. The medical device of  claim 1 , wherein the plurality of expandable legs are radially spaced from one another about the longitudinal axis of the medical device. 
     
     
       6. The medical device of  claim 1 , wherein the plurality of expandable legs are configured to deliver RF energy. 
     
     
       7. The medical device of  claim 1 , further including a distal tip, wherein the distal end of each of the plurality of expandable legs is coupled to the distal tip. 
     
     
       8. The medical device of  claim 7 , further including an actuating member that extends from the distal end of the elongate member, through a volume defined by the plurality of expandable legs, to the distal tip. 
     
     
       9. A medical device for delivering energy to a body lumen, the device comprising:
 a flexible elongate member comprising a proximal portion and a distal portion; and 
 an energy delivery device disposed at or adjacent the distal portion of the elongate member, the energy delivery device comprising at a plurality of electrodes, the energy delivery device being configured to move between an expanded state and a collapsed state; 
 wherein at least one of the plurality of electrodes comprises a proximal adjoining region, an active region disposed distally of the proximal adjoining region, and a distal adjoining region disposed distally of the active region, wherein the active region is configured to contact and deliver energy to the body lumen when the energy delivery device is in the expanded state; and 
 wherein, when the energy delivery device is in the collapsed state and while the energy delivery device is unconstrained by an outer sheath, at least a portion of the active region of the at least one electrode is pre-shaped such that it bows radially inward toward a longitudinal axis of the energy delivery device from both the proximal adjoining region and the distal adjoining region, such that at least a portion of the active region is closer to the longitudinal axis than at least a portion of the proximal adjoining region and at least a portion of the distal adjoining region, 
 wherein, when the energy delivery device is in the expanded state, distal ends of the plurality of electrodes converge toward one another. 
 
     
     
       10. The medical device of  claim 9 , wherein the proximal adjoining region and the distal adjoining region are either substantially flat or bow radially inward toward the longitudinal axis of the energy delivery device. 
     
     
       11. The medical device of  claim 9 , wherein, when the energy delivery device is in the expanded state, the active region becomes substantially flat, and at least a portion of the active region becomes positioned farther from the longitudinal axis than at least the portion of the proximal adjoining region and at least the portion of the distal adjoining region. 
     
     
       12. The medical device of  claim 9 , wherein the plurality of electrodes form an expandable basket assembly. 
     
     
       13. The medical device of  claim 1 , wherein, when the basket assembly is in the collapsed state, the active region of the first expandable leg, is convex with respect to the longitudinal axis of the medical device. 
     
     
       14. The medical device of  claim 1 , wherein the first and fourth regions of the first expandable leg are substantially flat in both the collapsed state and the expanded state of the basket assembly. 
     
     
       15. The medical device of  claim 9 , wherein the active region of the at least one electrode is convex with respect to the longitudinal axis of the energy delivery device when the energy delivery device is in the collapsed state. 
     
     
       16. The medical device of  claim 9 , wherein the plurality of electrodes are radially spaced from one another about the longitudinal axis of the energy delivery device. 
     
     
       17. The medical device of  claim 9 , wherein the plurality of electrodes are configured to deliver RF energy. 
     
     
       18. The medical device of  claim 9 , further including a distal tip, wherein the distal end of each of the plurality of electrodes is coupled to the distal tip. 
     
     
       19. The medical device of  claim 18 , further including an actuating member that extends from the distal end of the flexible elongate member, through a volume defined by the plurality of electrodes, to the distal tip.